1. Technical Field
The present invention relates to an ink jet printer.
2. Related Art
A piezo type ink jet printer adjusts weight of ink discharged from a head by adjusting a level of voltage applied to the head when discharging ink.
For example, in nanoimprint lithography using an ink jet method, a technique is proposed which suppresses variation of residual film thickness of a pattern transferred to a resist for each substrate by changing a voltage applied to a head according to the lot of functional ink (for example, see JP-A-2013-65624).
In an ink jet printer including a plurality of heads, even when the same voltage is applied to each head that discharges ink of the same color, weight of discharged ink varies for each head. When the weight of discharged ink varies for each head, there is a problem that density unevenness and the like occur in a printed matter. Further, even when ink is discharged from a single head by the same applied voltage, there is a problem that the weight of discharged ink is uneven due to temporal change of piezo and the like. Therefore, a technique is desired which suppresses variation of the weight of discharged ink, which is caused by individual difference and temporal change of the heads.